1. Field of the Invention
The present invention relates to a module having electronic components mounted thereon and a method of manufacturing the same.
2. Description of Related Art
Conventionally, there are known module substrates (modules), on which electronic components such as resistors and capacitors are mounted and which are used as a kind of integrated circuit. Such module substrates are mounted on wiring boards with other semiconductor devices and the like, and are incorporated in electronic devices. In these days, owing to the weight reduction of electronic devices, there is a demand for compact module substrates for use with such electronic devices. For this reason, as a method of manufacturing module substrates, from the viewpoint of easy handling in small sizes, conventionally, a method is employed with which a plurality of modules are formed on a same board, followed by division of the board into each module to obtain a plurality of module substrates at once.
A specific method of manufacturing a module substrate as described above proceeds as follows: first, on a board with predetermined wiring patterns formed thereon, electronic components are mounted so as to fit the corresponding wiring patterns; next, substantially the whole upper surface of the board is coated with a sealing resin layer such that the mounted electronic components are sealed; and then, the sealing resin layer and the board are cut with a dicing saw such that the board with the sealing resin layer formed thereon is divided into each module. In this way, a plurality of module substrates can be obtained. Such methods of manufacturing module substrates (modules) are disclosed, for example, in Japanese Unexamined Patent Application No. 2002-164658.
The conventional manufacturing method described above, however, suffers from a problem where the board warps, at the time of coating of the upper surface of the board with the sealing resin layer, due to contraction or expansion of the sealing resin layer during the hardening thereof and for other causes. The warp that has thus developed in the board makes it difficult to cut the board into each module. This leads to a problem of a decrease in cutting yield.